Can I run dex6 in my th400.
- Thread starter joegreen
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Originally Posted By: clinebarger
Direct Clutch.
TH400 Wave against piston, Flat Steel, Friction, Flat Steel, Friction, etc., Set clearance to .050"-.060".
I've assembled a bottom-up stack for the Direct Clutch that looks like this:
TH400 aluminum piston
TH400 wave
Flat steel
Friction
Flat steel
Friction
Flat steel
Friction
Flat steel
Friction
Flat steel
Friction
Backing plate
I did make the dual-feed mods including machining off the sealing ring ridges from the Center Support and also drilled 0.038" in the corner of the Direct Drum to prevent centrifugal apply. The high-rate CK return springs are also installed.
I've run into a question with the clutch clearance. It's a little awkward to measure and I'm coming up with about 0.042" if I lift up the top friction with a dial indicator measuring the movement. I get 0.048" if I measure down to the friction from the lip of the drum and subtract for the distance down from the drum lip to the face of the backing plate. I have a bit more confidence in the 0.048" number.
Is this close enough to 0.050" to be good, or should I substitute a 0.010" thinner flat steel and be closer to 0.058"?
Direct Clutch.
TH400 Wave against piston, Flat Steel, Friction, Flat Steel, Friction, etc., Set clearance to .050"-.060".
I've assembled a bottom-up stack for the Direct Clutch that looks like this:
TH400 aluminum piston
TH400 wave
Flat steel
Friction
Flat steel
Friction
Flat steel
Friction
Flat steel
Friction
Flat steel
Friction
Backing plate
I did make the dual-feed mods including machining off the sealing ring ridges from the Center Support and also drilled 0.038" in the corner of the Direct Drum to prevent centrifugal apply. The high-rate CK return springs are also installed.
I've run into a question with the clutch clearance. It's a little awkward to measure and I'm coming up with about 0.042" if I lift up the top friction with a dial indicator measuring the movement. I get 0.048" if I measure down to the friction from the lip of the drum and subtract for the distance down from the drum lip to the face of the backing plate. I have a bit more confidence in the 0.048" number.
Is this close enough to 0.050" to be good, or should I substitute a 0.010" thinner flat steel and be closer to 0.058"?
0.048" is fine,
What I do is set my dial indicator on the edge of the top friction splines & measure the friction movement along with the backing plate movement.
Another way is to seat the piston in the drum, Do not install the return spring assembly, Temporarily Stack it.....
Wave
Friction
Steel
Friction
Steel
Friction
Steel
Friction
Steel
Friction
Steel
Backing Plate
Insert a feeler gauge between the last steel & backing plate.....Accurate measurement without scarring up a friction, When done, Remove the Stack & install the return springs, Then stack the frictions & steels in the correct order.
What I do is set my dial indicator on the edge of the top friction splines & measure the friction movement along with the backing plate movement.
Another way is to seat the piston in the drum, Do not install the return spring assembly, Temporarily Stack it.....
Wave
Friction
Steel
Friction
Steel
Friction
Steel
Friction
Steel
Friction
Steel
Backing Plate
Insert a feeler gauge between the last steel & backing plate.....Accurate measurement without scarring up a friction, When done, Remove the Stack & install the return springs, Then stack the frictions & steels in the correct order.
Thanks, I think I'll run with 0.048"!
I attempted the feeler-gauge method, but the springiness of the wave and worry of damaging the friction prompted my tying something else.
Slowly working my way forward, I just discovered that the 4th clutch outer housing has some deep divots and scarring from where the tangs of the steels engage in the notches. It's bad enough that I'm planning to replace it, but just wondering if this is typical of high mileage wear or if there is some other possible issue causing it?
I attempted the feeler-gauge method, but the springiness of the wave and worry of damaging the friction prompted my tying something else.
Slowly working my way forward, I just discovered that the 4th clutch outer housing has some deep divots and scarring from where the tangs of the steels engage in the notches. It's bad enough that I'm planning to replace it, but just wondering if this is typical of high mileage wear or if there is some other possible issue causing it?
Originally Posted By: JiL
Slowly working my way forward, I just discovered that the 4th clutch outer housing has some deep divots and scarring from where the tangs of the steels engage in the notches. It's bad enough that I'm planning to replace it, but just wondering if this is typical of high mileage wear or if there is some other possible issue causing it?
It's mileage wear, Specifically the trans is in 4th gear & the converter is locked & the harmonics from the engine transfer through the Turbine Shaft into the O/D unit. 4L80E's behind diesel engines are the worse for that kind of wear.
'91-mid year '99 O/D Clutch Housings are different than Late '99 & up, The late housing's Backing Plate has a hook on it that engages the Dowel Pin in the case, The early Housing has no hook & the case has no dowel.
Slowly working my way forward, I just discovered that the 4th clutch outer housing has some deep divots and scarring from where the tangs of the steels engage in the notches. It's bad enough that I'm planning to replace it, but just wondering if this is typical of high mileage wear or if there is some other possible issue causing it?
It's mileage wear, Specifically the trans is in 4th gear & the converter is locked & the harmonics from the engine transfer through the Turbine Shaft into the O/D unit. 4L80E's behind diesel engines are the worse for that kind of wear.
'91-mid year '99 O/D Clutch Housings are different than Late '99 & up, The late housing's Backing Plate has a hook on it that engages the Dowel Pin in the case, The early Housing has no hook & the case has no dowel.
Thanks, that does sound plausible. The divots are rough and choppy.
The Forward pack is assembled now too similarly to the Direct. TH400 piston and wave, five pairs of frictions and steels, stock TH400 return springs and a clearance of 0.047".
Once the 4th clutch is together, assembly and end-play checking should be next.
The Forward pack is assembled now too similarly to the Direct. TH400 piston and wave, five pairs of frictions and steels, stock TH400 return springs and a clearance of 0.047".
Once the 4th clutch is together, assembly and end-play checking should be next.
After setting rear endplay to 0.005" (rollerized) and torquing the Center Support bolt, when rotating the output shaft it has a slight bind in the same location relative to the case. It's not so tight that it can't be turned past it by hand, but it's there. It takes more effort to rotate past it when turning CW (looking at the output) vs. CCW.
When it gets tight, the hollow sun gear shaft stops turning opposite to the output and is stationary. If I remove the hollow shaft, the output turns freely.
Wondering if one of the bushings might have a burr or something that's causing a bind. . .
When it gets tight, the hollow sun gear shaft stops turning opposite to the output and is stationary. If I remove the hollow shaft, the output turns freely.
Wondering if one of the bushings might have a burr or something that's causing a bind. . .
Do you have to work the Sun Gear Shaft in the trans? It should just slide in. If not....One of the Sun Gear Shaft bushings has a high spot or sitting in the bore crooked. The Center Support bushing can also drag on the sun gear shaft.
How are you installing the bushings?
How are you installing the bushings?
Today i got the forward clutch pack setup and i have a few questions on what i did. First off i am using the atsg manual and ron sessions how to work with and modify the th400. The atsg manual says to use a clearance of .010" for every friction used which would lead me to set the forward clutch pack at .050" clearance. 
Ron sessions book gives a different spec for the "ideal" forward clutch pack clearance.
I used a .0600" waved plate on the bottom and all the other steels are the thin .077". I got a total clearance of about .046" to .047". Im not sure if i should leave it at that or try to decrease the clutch pack clearance per ron sessions book?
I measured the clutch hub thickness where the friction would touch and it measured .162". I found two steel plates that when added together came out to .163". I used those two steels on the top of the friction and then used a dial indicator and compressed air to get my clutch clearance measurement of .046-.047. Did i measure that properly? I used two steel plates instead of the hub because the hub could not drop all the way down on top of the frictions because of a little lip on the drum.
Ron sessions book gives a different spec for the "ideal" forward clutch pack clearance.
I used a .0600" waved plate on the bottom and all the other steels are the thin .077". I got a total clearance of about .046" to .047". Im not sure if i should leave it at that or try to decrease the clutch pack clearance per ron sessions book?
I measured the clutch hub thickness where the friction would touch and it measured .162". I found two steel plates that when added together came out to .163". I used those two steels on the top of the friction and then used a dial indicator and compressed air to get my clutch clearance measurement of .046-.047. Did i measure that properly? I used two steel plates instead of the hub because the hub could not drop all the way down on top of the frictions because of a little lip on the drum.
Originally Posted By: clinebarger
Do you have to work the Sun Gear Shaft in the trans? It should just slide in.
When it's not at the tight spot it slides very smoothly.
Originally Posted By: clinebarger
If not....One of the Sun Gear Shaft bushings has a high spot or sitting in the bore crooked.
Rotating the sun gear shaft by itself on the mainshaft is very smooth.
Originally Posted By: clinebarger
The Center Support bushing can also drag on the sun gear shaft.
Outside of the case, with just the sun gear shaft in the center support it rotates freely.
Originally Posted By: clinebarger
How are you installing the bushings?
Hydraulic press.
One reason I was suspecting a bushing is the replacement front planet that I got had a ding on the edge of the bushing bore that I overlooked until seeing that the new bushing had hung up on it when installed. I thought it had been smoothed out sufficiently, but perhaps not. That bushing also doesn't appear to have been made well. The shell joining seam wasn't very smooth and the central oil groove isn't well aligned. I'm going to replace it as a starting point.
Do you have to work the Sun Gear Shaft in the trans? It should just slide in.
When it's not at the tight spot it slides very smoothly.
Originally Posted By: clinebarger
If not....One of the Sun Gear Shaft bushings has a high spot or sitting in the bore crooked.
Rotating the sun gear shaft by itself on the mainshaft is very smooth.
Originally Posted By: clinebarger
The Center Support bushing can also drag on the sun gear shaft.
Outside of the case, with just the sun gear shaft in the center support it rotates freely.
Originally Posted By: clinebarger
How are you installing the bushings?
Hydraulic press.
One reason I was suspecting a bushing is the replacement front planet that I got had a ding on the edge of the bushing bore that I overlooked until seeing that the new bushing had hung up on it when installed. I thought it had been smoothed out sufficiently, but perhaps not. That bushing also doesn't appear to have been made well. The shell joining seam wasn't very smooth and the central oil groove isn't well aligned. I'm going to replace it as a starting point.
Originally Posted By: joegreen
Today i got the forward clutch pack setup and i have a few questions on what i did. First off i am using the atsg manual and ron sessions how to work with and modify the th400. The atsg manual says to use a clearance of .010" for every friction used which would lead me to set the forward clutch pack at .050" clearance.
Ron sessions book gives a different spec for the "ideal" forward clutch pack clearance.
I used a .0600" waved plate on the bottom and all the other steels are the thin .077". I got a total clearance of about .046" to .047". Im not sure if i should leave it at that or try to decrease the clutch pack clearance per ron sessions book?
I measured the clutch hub thickness where the friction would touch and it measured .162". I found two steel plates that when added together came out to .163". I used those two steels on the top of the friction and then used a dial indicator and compressed air to get my clutch clearance measurement of .046-.047. Did i measure that properly? I used two steel plates instead of the hub because the hub could not drop all the way down on top of the frictions because of a little lip on the drum.
Before I go off..... Your .046-.047. measured clearance is good, Your method of measuring seems sound....Don't change a thing.
I use the .010" per friction rule on TH400/4L80E's.....Especially when using flat faced frictions. The Forward Hub & Forward Frictions overrun in reverse, They NEED room to separate & freewheel.
As little as .030" is permissible on A LOT of units for the Forward Clutch....But not on TH400/4L80E & here is why.
In reverse, The directs are applied allowing the forward clutch drum to "drive" the direct drum via the direct clutch hub that is also the backing plate for the forward clutch.
With the direct frictions clamped down on the direct clutch hub, It can no longer float in the forward drum, This is why there is a stop machined in the drum....To keep the direct clutch hub from dragging on the frictions.
IF you run to tight a clearance the top friction will end up ABOVE the stop with the direct clutch hub resting right on the friction with no way for them to separate & cleanly overrun.
I am not dragging anyone's build techniques through the mud.....To many builders try the same techniques on every unit when they need to have a good handle on the operational differences before making engineering changes in the name of durability/comfort.
I know why Ron states that tight of clearance.....To soften the "garage shift" into forward gears, The tighter clearance prevents the piston from building to much speed & slamming into the clutch pack, This gets exaggerated with a higher minimum regulated line pressure from heavy pressure regulator springs &/or omitting the wave plate.
With luxury vehicles/picky customers/big cam cars that idle real high & don't make any horsepower.....
I run 2 or 3 wave plates in the forward clutch.
On big power & extreme heavy duty vehicles that need all the forward clamping force available....I run what's referred to as a "Feed-Bleed" set-up. I take a aluminum TH400 piston that has a checkball in it, Drill out the checkball retaining tabs, Install a steel cup plug & drill a .020"-.030" hole in the cup plug depending on the application.
The fluid exhausted from the bleed hole slows down the piston 'til the wave flattens out & plugs the bleed orifice.
A picture of my personal 4L80E forward piston with the feed-bleed set-up.....Softer apply, Maximum clamping, Adequate clearance.
Today i got the forward clutch pack setup and i have a few questions on what i did. First off i am using the atsg manual and ron sessions how to work with and modify the th400. The atsg manual says to use a clearance of .010" for every friction used which would lead me to set the forward clutch pack at .050" clearance.
Ron sessions book gives a different spec for the "ideal" forward clutch pack clearance.
I used a .0600" waved plate on the bottom and all the other steels are the thin .077". I got a total clearance of about .046" to .047". Im not sure if i should leave it at that or try to decrease the clutch pack clearance per ron sessions book?
I measured the clutch hub thickness where the friction would touch and it measured .162". I found two steel plates that when added together came out to .163". I used those two steels on the top of the friction and then used a dial indicator and compressed air to get my clutch clearance measurement of .046-.047. Did i measure that properly? I used two steel plates instead of the hub because the hub could not drop all the way down on top of the frictions because of a little lip on the drum.
Before I go off..... Your .046-.047. measured clearance is good, Your method of measuring seems sound....Don't change a thing.
I use the .010" per friction rule on TH400/4L80E's.....Especially when using flat faced frictions. The Forward Hub & Forward Frictions overrun in reverse, They NEED room to separate & freewheel.
As little as .030" is permissible on A LOT of units for the Forward Clutch....But not on TH400/4L80E & here is why.
In reverse, The directs are applied allowing the forward clutch drum to "drive" the direct drum via the direct clutch hub that is also the backing plate for the forward clutch.
With the direct frictions clamped down on the direct clutch hub, It can no longer float in the forward drum, This is why there is a stop machined in the drum....To keep the direct clutch hub from dragging on the frictions.
IF you run to tight a clearance the top friction will end up ABOVE the stop with the direct clutch hub resting right on the friction with no way for them to separate & cleanly overrun.
I am not dragging anyone's build techniques through the mud.....To many builders try the same techniques on every unit when they need to have a good handle on the operational differences before making engineering changes in the name of durability/comfort.
I know why Ron states that tight of clearance.....To soften the "garage shift" into forward gears, The tighter clearance prevents the piston from building to much speed & slamming into the clutch pack, This gets exaggerated with a higher minimum regulated line pressure from heavy pressure regulator springs &/or omitting the wave plate.
With luxury vehicles/picky customers/big cam cars that idle real high & don't make any horsepower.....
I run 2 or 3 wave plates in the forward clutch.
On big power & extreme heavy duty vehicles that need all the forward clamping force available....I run what's referred to as a "Feed-Bleed" set-up. I take a aluminum TH400 piston that has a checkball in it, Drill out the checkball retaining tabs, Install a steel cup plug & drill a .020"-.030" hole in the cup plug depending on the application.
The fluid exhausted from the bleed hole slows down the piston 'til the wave flattens out & plugs the bleed orifice.
A picture of my personal 4L80E forward piston with the feed-bleed set-up.....Softer apply, Maximum clamping, Adequate clearance.
Originally Posted By: JiL
Originally Posted By: clinebarger
Do you have to work the Sun Gear Shaft in the trans? It should just slide in.
When it's not at the tight spot it slides very smoothly.
Originally Posted By: clinebarger
If not....One of the Sun Gear Shaft bushings has a high spot or sitting in the bore crooked.
Rotating the sun gear shaft by itself on the mainshaft is very smooth.
Originally Posted By: clinebarger
The Center Support bushing can also drag on the sun gear shaft.
Outside of the case, with just the sun gear shaft in the center support it rotates freely.
Originally Posted By: clinebarger
How are you installing the bushings?
Hydraulic press.
One reason I was suspecting a bushing is the replacement front planet that I got had a ding on the edge of the bushing bore that I overlooked until seeing that the new bushing had hung up on it when installed. I thought it had been smoothed out sufficiently, but perhaps not. That bushing also doesn't appear to have been made well. The shell joining seam wasn't very smooth and the central oil groove isn't well aligned. I'm going to replace it as a starting point.
The front/reaction planet bushing makes sense! Turning the output one direction causes the the lo/reverse roller clutch to hold the front planet stationary. (hard direction), The other direction....The front planet free wheels. (easy direction). A bind would make it stall out.
Originally Posted By: clinebarger
Do you have to work the Sun Gear Shaft in the trans? It should just slide in.
When it's not at the tight spot it slides very smoothly.
Originally Posted By: clinebarger
If not....One of the Sun Gear Shaft bushings has a high spot or sitting in the bore crooked.
Rotating the sun gear shaft by itself on the mainshaft is very smooth.
Originally Posted By: clinebarger
The Center Support bushing can also drag on the sun gear shaft.
Outside of the case, with just the sun gear shaft in the center support it rotates freely.
Originally Posted By: clinebarger
How are you installing the bushings?
Hydraulic press.
One reason I was suspecting a bushing is the replacement front planet that I got had a ding on the edge of the bushing bore that I overlooked until seeing that the new bushing had hung up on it when installed. I thought it had been smoothed out sufficiently, but perhaps not. That bushing also doesn't appear to have been made well. The shell joining seam wasn't very smooth and the central oil groove isn't well aligned. I'm going to replace it as a starting point.
The front/reaction planet bushing makes sense! Turning the output one direction causes the the lo/reverse roller clutch to hold the front planet stationary. (hard direction), The other direction....The front planet free wheels. (easy direction). A bind would make it stall out.
So the feed bleed setup just softens the initial apply of putting it into gear when the idle is a little high? If the idle is a little high and the 1st gear engagement feels a little hard is that ok. Is the feed bleed you do just so the trans engagement feels better to the customer or is it bad for the 1st gear to lock up a little harsh?
I have a couple questions on a rear bushing i bought. Without going back through 8 pages of text i think it was you clinebarger that said the 4l80e pump busing would work as the rear bushing and because it was longer would help locate the th350 pump thrust bearing if i decide to rollerize the rear. I bought a .700" 4l80e pump bushing. I noticed the inside of the stock bushing has grooves for oil but the 4l80e bushing just has a smooth inside surface. Is it still ok to use the 4l80e bushing? should i put grooves into the 4l80e bushing? What material is the 4l80e bushing made from?
Now as far as rollerizing the rear i have a few concerns. I have all the parts if i decide to rollerize or run the thrust washer. My main concern in reliability. The thrust washer seems pretty fool proof with no moving parts and i have the sonnax no walk rear bushing. I read online that while very rare some people have had the rear thrust washer fail and drop a bearing or something and then it totally screws up the bearing and rear section and endplay. This truck is my daily driver used to commute to school, work, and plow my driveway. I dont drive a whole lot and i have only put just under 10,000 miles on it since i bought it in 2012.
How long does a thrust washer take to wear out?
Should i do the thrust bearing or thrust washer setup?
If i do the thrust bearing how do keep the rear bushing from possibly walking?
I have a couple questions on a rear bushing i bought. Without going back through 8 pages of text i think it was you clinebarger that said the 4l80e pump busing would work as the rear bushing and because it was longer would help locate the th350 pump thrust bearing if i decide to rollerize the rear. I bought a .700" 4l80e pump bushing. I noticed the inside of the stock bushing has grooves for oil but the 4l80e bushing just has a smooth inside surface. Is it still ok to use the 4l80e bushing? should i put grooves into the 4l80e bushing? What material is the 4l80e bushing made from?
Now as far as rollerizing the rear i have a few concerns. I have all the parts if i decide to rollerize or run the thrust washer. My main concern in reliability. The thrust washer seems pretty fool proof with no moving parts and i have the sonnax no walk rear bushing. I read online that while very rare some people have had the rear thrust washer fail and drop a bearing or something and then it totally screws up the bearing and rear section and endplay. This truck is my daily driver used to commute to school, work, and plow my driveway. I dont drive a whole lot and i have only put just under 10,000 miles on it since i bought it in 2012.
How long does a thrust washer take to wear out?
Should i do the thrust bearing or thrust washer setup?
If i do the thrust bearing how do keep the rear bushing from possibly walking?
Originally Posted By: joegreen
So the feed bleed setup just softens the initial apply of putting it into gear when the idle is a little high? If the idle is a little high and the 1st gear engagement feels a little hard is that ok. Is the feed bleed you do just so the trans engagement feels better to the customer or is it bad for the 1st gear to lock up a little harsh?
It's mostly for customer complaints.....I personally don't like harsh engagements either.
High Idle, Low Vacuum, Misadjusted Modulator, And Elevated base Line Pressure from aftermarket PR Springs can/will cause harsh forward engagement.
TH400's are very stout units & can tolerate a lot of abuse, The only internal trans part I would be concerned about is the Cast Iron Forward Hub splines that engage the Main Shaft....Even then it would take a few thousand harsh engagements to wipe the splines. GM switched to Steel hubs in 4L80E's for this reason.
The Transfer Case & U-Joints are the drivetrian parts that will suffer the most. But I digress.....In you case with a stock truck, I highly doubt you will have any problems with the forward clearance you have with no other modifications to the forward clutch circuit.
Originally Posted By: joegreen
I have a couple questions on a rear bushing i bought. Without going back through 8 pages of text i think it was you clinebarger that said the 4l80e pump busing would work as the rear bushing and because it was longer would help locate the th350 pump thrust bearing if i decide to rollerize the rear. I bought a .700" 4l80e pump bushing. I noticed the inside of the stock bushing has grooves for oil but the 4l80e bushing just has a smooth inside surface. Is it still ok to use the 4l80e bushing? should i put grooves into the 4l80e bushing? What material is the 4l80e bushing made from?
Yes, It was me, I use the .700" 4L80E pump bushing on most TH400 builds.
I extensively tested the use of this bushing in a wide range of uses....Heavy Towing, Vocational, Street Sweepers, And I shipped quite a few to a customer in Minnesota that puts them in Plow Trucks. I have not seen or had to warranty a bushing failure.....ALL of them were Rollerized as well.
The factory bushing gets installed backwards as much as it gets installed correctly, If you look at your TH400 bushing you will notice that it has lube entrance flutes on 1 side but not the other, The flutes are suppose to face the inside of the case. They don't fail with any greater frequency being installed backwards.
Case Bushing walk-out is caused by driveline harmonics/vibrations, Very rare to see on a 4wd trans as the driveline is not attached directly to the output shaft.
I use either red loctite or retaining compound on the OD of the bushing before driving it home.
Not sure on exactly what the 4L80E pump bushing material is, There are different ones available in the aftermarket.....The good news is, I use/used that same dull grey finished one like you have
Originally Posted By: joegreen
Now as far as rollerizing the rear i have a few concerns. I have all the parts if i decide to rollerize or run the thrust washer. My main concern in reliability. The thrust washer seems pretty fool proof with no moving parts and i have the sonnax no walk rear bushing. I read online that while very rare some people have had the rear thrust washer fail and drop a bearing or something and then it totally screws up the bearing and rear section and endplay. This truck is my daily driver used to commute to school, work, and plow my driveway. I dont drive a whole lot and i have only put just under 10,000 miles on it since i bought it in 2012.
How long does a thrust washer take to wear out?
Should i do the thrust bearing or thrust washer setup?
If i do the thrust bearing how do keep the rear bushing from possibly walking?
I would have to see the failure before saying it was this or that being the cause, But if I were to guess.....To much or NO rear unit end-play. To much would cause the entire geartrain to ram into the bearing, No end-play would cause constant pressure on the bearing that would only increase as the unit heats up.
Another concern would be no lube oil making it to the bearing....I have seen this caused by someone installing a solid mainshaft out of a late 4L80E in a TH400.
Installing the bearing upside down would cause the bearing race to eat through the bushing & drop the bearing out.
I would without a doubt or concern.....Rollerize the output!! Your rear unit end-play will stay constant for a lot longer, Less friction, And Less contaminates in the ATF.
With that said....The thrust set-up will last a long time in all but the most demanding applications.
So the feed bleed setup just softens the initial apply of putting it into gear when the idle is a little high? If the idle is a little high and the 1st gear engagement feels a little hard is that ok. Is the feed bleed you do just so the trans engagement feels better to the customer or is it bad for the 1st gear to lock up a little harsh?
It's mostly for customer complaints.....I personally don't like harsh engagements either.
High Idle, Low Vacuum, Misadjusted Modulator, And Elevated base Line Pressure from aftermarket PR Springs can/will cause harsh forward engagement.
TH400's are very stout units & can tolerate a lot of abuse, The only internal trans part I would be concerned about is the Cast Iron Forward Hub splines that engage the Main Shaft....Even then it would take a few thousand harsh engagements to wipe the splines. GM switched to Steel hubs in 4L80E's for this reason.
The Transfer Case & U-Joints are the drivetrian parts that will suffer the most. But I digress.....In you case with a stock truck, I highly doubt you will have any problems with the forward clearance you have with no other modifications to the forward clutch circuit.
Originally Posted By: joegreen
I have a couple questions on a rear bushing i bought. Without going back through 8 pages of text i think it was you clinebarger that said the 4l80e pump busing would work as the rear bushing and because it was longer would help locate the th350 pump thrust bearing if i decide to rollerize the rear. I bought a .700" 4l80e pump bushing. I noticed the inside of the stock bushing has grooves for oil but the 4l80e bushing just has a smooth inside surface. Is it still ok to use the 4l80e bushing? should i put grooves into the 4l80e bushing? What material is the 4l80e bushing made from?
Yes, It was me, I use the .700" 4L80E pump bushing on most TH400 builds.
I extensively tested the use of this bushing in a wide range of uses....Heavy Towing, Vocational, Street Sweepers, And I shipped quite a few to a customer in Minnesota that puts them in Plow Trucks. I have not seen or had to warranty a bushing failure.....ALL of them were Rollerized as well.
The factory bushing gets installed backwards as much as it gets installed correctly, If you look at your TH400 bushing you will notice that it has lube entrance flutes on 1 side but not the other, The flutes are suppose to face the inside of the case. They don't fail with any greater frequency being installed backwards.
Case Bushing walk-out is caused by driveline harmonics/vibrations, Very rare to see on a 4wd trans as the driveline is not attached directly to the output shaft.
I use either red loctite or retaining compound on the OD of the bushing before driving it home.
Not sure on exactly what the 4L80E pump bushing material is, There are different ones available in the aftermarket.....The good news is, I use/used that same dull grey finished one like you have
Originally Posted By: joegreen
Now as far as rollerizing the rear i have a few concerns. I have all the parts if i decide to rollerize or run the thrust washer. My main concern in reliability. The thrust washer seems pretty fool proof with no moving parts and i have the sonnax no walk rear bushing. I read online that while very rare some people have had the rear thrust washer fail and drop a bearing or something and then it totally screws up the bearing and rear section and endplay. This truck is my daily driver used to commute to school, work, and plow my driveway. I dont drive a whole lot and i have only put just under 10,000 miles on it since i bought it in 2012.
How long does a thrust washer take to wear out?
Should i do the thrust bearing or thrust washer setup?
If i do the thrust bearing how do keep the rear bushing from possibly walking?
I would have to see the failure before saying it was this or that being the cause, But if I were to guess.....To much or NO rear unit end-play. To much would cause the entire geartrain to ram into the bearing, No end-play would cause constant pressure on the bearing that would only increase as the unit heats up.
Another concern would be no lube oil making it to the bearing....I have seen this caused by someone installing a solid mainshaft out of a late 4L80E in a TH400.
Installing the bearing upside down would cause the bearing race to eat through the bushing & drop the bearing out.
I would without a doubt or concern.....Rollerize the output!! Your rear unit end-play will stay constant for a lot longer, Less friction, And Less contaminates in the ATF.
With that said....The thrust set-up will last a long time in all but the most demanding applications.
I have a few more questions.
1. The bushing that goes on the back of the output shaft should that notch circled be facing up or down?
2. Also that is a new bushing i installed but i did not have ron sessions book yet when i installed it. What i mean by that is the book says to install the bushing .070" below the surface which i did not do and i now see why i need to do it because the thrust bearing race lip runs into the bushing when its flush with the surface. I used red loctite when i installed it. Do i need to put another bushing in or can i just tap the bushing down to the proper depth below the surface?
3. The surface from the rear internal ring gear that rides on the bushing above is all galled with deep grooves you can feel easily with your fingernail. Everything circled in red is the galled surface and everything circled in blue is the smooth surface. Should i replace this rear ring gear?
4. Below talks about pushing the spring loaded side of the ball in the foward drum. My ball does not have a spring behind it and neither does the direct drum. It just moves in its hole when you shake the drum. Is it supposed to have a spring behind the check ball?
5. It says to use aluminum replacement sealing rings on the accumulator piston. My rebuild kit only came with cast iron rings and the rings that were on the accumulator before were also cast iron and the aluminum where the ring rides looks great. I couldn't find anything online about any aluminum sealing rings. Is it ok to use the cast iron sealing ring or should i get a teflon ring?
1. The bushing that goes on the back of the output shaft should that notch circled be facing up or down?
2. Also that is a new bushing i installed but i did not have ron sessions book yet when i installed it. What i mean by that is the book says to install the bushing .070" below the surface which i did not do and i now see why i need to do it because the thrust bearing race lip runs into the bushing when its flush with the surface. I used red loctite when i installed it. Do i need to put another bushing in or can i just tap the bushing down to the proper depth below the surface?
3. The surface from the rear internal ring gear that rides on the bushing above is all galled with deep grooves you can feel easily with your fingernail. Everything circled in red is the galled surface and everything circled in blue is the smooth surface. Should i replace this rear ring gear?
4. Below talks about pushing the spring loaded side of the ball in the foward drum. My ball does not have a spring behind it and neither does the direct drum. It just moves in its hole when you shake the drum. Is it supposed to have a spring behind the check ball?
5. It says to use aluminum replacement sealing rings on the accumulator piston. My rebuild kit only came with cast iron rings and the rings that were on the accumulator before were also cast iron and the aluminum where the ring rides looks great. I couldn't find anything online about any aluminum sealing rings. Is it ok to use the cast iron sealing ring or should i get a teflon ring?
Another question. The mainshaft looks like it has a cup plug in the end but according to the book it says only 69 and earlier models have the cup plug. Does this look like a cup plug?
Also the book says to remove the cup plug for added oil flow to the gearset. Considering this book is fairly old is it still a good idea to remove the cup plug if i indeed have one?
The book also says to check the sun gear shaft in the reaction carrier bushing. Is that a mistake? I circled what i think is the reaction carrier bushing and the sun gear shaft is multitudes smaller than the reaction carrier bushing. I thought the sun gear shaft went in the center support bushing?
Also the book says to remove the cup plug for added oil flow to the gearset. Considering this book is fairly old is it still a good idea to remove the cup plug if i indeed have one?
The book also says to check the sun gear shaft in the reaction carrier bushing. Is that a mistake? I circled what i think is the reaction carrier bushing and the sun gear shaft is multitudes smaller than the reaction carrier bushing. I thought the sun gear shaft went in the center support bushing?
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Originally Posted By: joegreen
would this ring gear work even though its from a 67? http://www.ebay.com/itm/67-rear-ring-gear-th400-transmission-oldsmobile-/172227839411?hash=item28199445b3:g:zSQAAOSw9eVXUFKr&vxp=mtr
Yes, It will work IF your carrier pinions are Helical Cut, If you have Straight Cut pinions it will not fit. What is wrong with your ring gear?
would this ring gear work even though its from a 67? http://www.ebay.com/itm/67-rear-ring-gear-th400-transmission-oldsmobile-/172227839411?hash=item28199445b3:g:zSQAAOSw9eVXUFKr&vxp=mtr
Yes, It will work IF your carrier pinions are Helical Cut, If you have Straight Cut pinions it will not fit. What is wrong with your ring gear?
Originally Posted By: joegreen
Another question. The mainshaft looks like it has a cup plug in the end but according to the book it says only 69 and earlier models have the cup plug. Does this look like a cup plug?
Also the book says to remove the cup plug for added oil flow to the gearset. Considering this book is fairly old is it still a good idea to remove the cup plug if i indeed have one?
The book also says to check the sun gear shaft in the reaction carrier bushing. Is that a mistake? I circled what i think is the reaction carrier bushing and the sun gear shaft is multitudes smaller than the reaction carrier bushing. I thought the sun gear shaft went in the center support bushing?
Yes, That is Orificed Cup Plug....Remove it! I'm highly surprised to see that in your trans. TH400's were not installed in trucks in great volume 'til 1969....That's when geartrians started melting down from lube starvation. Good attention to detail Joe!
I think he meant to say Center Support Bushing.....
Insert the Sun Gear Shaft into the Center Support, Check for wobble.
Insert the Main Shaft into the Sun Gear Shaft, Check for wobble.
Place the Center Support over the Reaction Carrier without the Lo Roller Clutch & check the bushing.
Place the Rear Internal Gear on the Output Shaft & check that bushing as well.
I replace ALL the bushings no matter what, But I understand not have all the correct Dies makes it pretty tough.
Another question. The mainshaft looks like it has a cup plug in the end but according to the book it says only 69 and earlier models have the cup plug. Does this look like a cup plug?
Also the book says to remove the cup plug for added oil flow to the gearset. Considering this book is fairly old is it still a good idea to remove the cup plug if i indeed have one?
The book also says to check the sun gear shaft in the reaction carrier bushing. Is that a mistake? I circled what i think is the reaction carrier bushing and the sun gear shaft is multitudes smaller than the reaction carrier bushing. I thought the sun gear shaft went in the center support bushing?
Yes, That is Orificed Cup Plug....Remove it! I'm highly surprised to see that in your trans. TH400's were not installed in trucks in great volume 'til 1969....That's when geartrians started melting down from lube starvation. Good attention to detail Joe!
I think he meant to say Center Support Bushing.....
Insert the Sun Gear Shaft into the Center Support, Check for wobble.
Insert the Main Shaft into the Sun Gear Shaft, Check for wobble.
Place the Center Support over the Reaction Carrier without the Lo Roller Clutch & check the bushing.
Place the Rear Internal Gear on the Output Shaft & check that bushing as well.
I replace ALL the bushings no matter what, But I understand not have all the correct Dies makes it pretty tough.
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